Rio de Janeiro (AP) - His meet-and-greet with the U.S. president was bumped to Saturday, and when the White House announced his official visit, they misspelled his name. But when Brazilian President Luiz Inacio Lula da Silva becomes the first Latin American leader to sit down with President Barack Obama this weekend, he brings undisputed clout. Silva runs the world's fifth-most-populous nation and ninth-largest economy and has close ties with leaders across the political spectrum. He's been asked to lobby Obama for free trade on behalf of conservatives in Colombia and for dropping the U.S. embargo against communist Cuba. Even...